BMC/Intel-BMC/linux.git/arch/s390/include/asm/tlb.h, branch dev

s390: remove 31 bit support

2015-03-25T10:49:33+00:00

Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/mm: fix memory leak of ptlock in pmd_free_tlb

2014-12-08T08:42:40+00:00

The pmd_free_tlb function fails to call pgtable_pmd_page_dtor. Without the call the ptlock for the pmd tables will not be freed. Add the missing call. Signed-off-by: Martin Schwidefsky

KVM: s390/mm: use radix trees for guest to host mappings

2014-08-26T08:09:02+00:00

Store the target address for the gmap segments in a radix tree instead of using invalid segment table entries. gmap_translate becomes a simple radix_tree_lookup, gmap_fault is split into the address translation with gmap_translate and the part that does the linking of the gmap shadow page table with the process page table. A second radix tree is used to keep the pointers to the segment table entries for segments that are mapped in the guest address space. On unmap of a segment the pointer is retrieved from the radix tree and is used to carry out the segment invalidation in the gmap shadow page table. As the radix tree can only store one pointer, each host segment may only be mapped to exactly one guest location. Signed-off-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger

mm: split 'tlb_flush_mmu()' into tlb flushing and memory freeing parts

2014-04-25T23:05:40+00:00

The mmu-gather operation 'tlb_flush_mmu()' has done two things: the actual tlb flush operation, and the batched freeing of the pages that the TLB entries pointed at. This splits the operation into separate phases, so that the forced batched flushing done by zap_pte_range() can now do the actual TLB flush while still holding the page table lock, but delay the batched freeing of all the pages to after the lock has been dropped. This in turn allows us to avoid a race condition between set_page_dirty() (as called by zap_pte_range() when it finds a dirty shared memory pte) and page_mkclean(): because we now flush all the dirty page data from the TLB's while holding the pte lock, page_mkclean() will be held up walking the (recently cleaned) page tables until after the TLB entries have been flushed from all CPU's. Reported-by: Benjamin Herrenschmidt Tested-by: Dave Hansen Acked-by: Hugh Dickins Cc: Peter Zijlstra Cc: Russell King - ARM Linux Cc: Tony Luck Signed-off-by: Linus Torvalds

s390/mm,tlb: safeguard against speculative TLB creation

2014-04-03T12:30:55+00:00

The principles of operations states that the CPU is allowed to create TLB entries for an address space anytime while an ASCE is loaded to the control register. This is true even if the CPU is running in the kernel and the user address space is not (actively) accessed. In theory this can affect two aspects of the TLB flush logic. For full-mm flushes the ASCE of the dying process is still attached. The approach to flush first with IDTE and then just free all page tables can in theory lead to stale TLB entries. Use the batched free of page tables for the full-mm flushes as well. For operations that can have a stale ASCE in the control register, e.g. a delayed update_user_asce in switch_mm, load the kernel ASCE to prevent invalid TLBs from being created. Signed-off-by: Martin Schwidefsky

s390/mm: introduce ptep_flush_lazy helper

2013-08-22T10:20:09+00:00

Isolate the logic of IDTE vs. IPTE flushing of ptes in two functions, ptep_flush_lazy and __tlb_flush_mm_lazy. Signed-off-by: Martin Schwidefsky

s390: Fix broken build

2013-08-17T04:16:37+00:00

Fix this build error: In file included from fs/exec.c:61:0: arch/s390/include/asm/tlb.h:35:23: error: expected identifier or '(' before 'unsigned' arch/s390/include/asm/tlb.h:36:1: warning: no semicolon at end of struct or union [enabled by default] arch/s390/include/asm/tlb.h: In function 'tlb_gather_mmu': arch/s390/include/asm/tlb.h:57:5: error: 'struct mmu_gather' has no member named 'end' Broken due to commit 2b047252d0 ("Fix TLB gather virtual address range invalidation corner cases"). Cc: Greg Kroah-Hartman Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck [ Oh well. We had build testing for ppc amd um, but no s390 - Linus ] Signed-off-by: Linus Torvalds

Fix TLB gather virtual address range invalidation corner cases

2013-08-16T15:52:46+00:00

Ben Tebulin reported: "Since v3.7.2 on two independent machines a very specific Git repository fails in 9/10 cases on git-fsck due to an SHA1/memory failures. This only occurs on a very specific repository and can be reproduced stably on two independent laptops. Git mailing list ran out of ideas and for me this looks like some very exotic kernel issue" and bisected the failure to the backport of commit 53a59fc67f97 ("mm: limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT"). That commit itself is not actually buggy, but what it does is to make it much more likely to hit the partial TLB invalidation case, since it introduces a new case in tlb_next_batch() that previously only ever happened when running out of memory. The real bug is that the TLB gather virtual memory range setup is subtly buggered. It was introduced in commit 597e1c3580b7 ("mm/mmu_gather: enable tlb flush range in generic mmu_gather"), and the range handling was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB range flushed when __tlb_remove_page() runs out of slots"), but that fix was not complete. The problem with the TLB gather virtual address range is that it isn't set up by the initial tlb_gather_mmu() initialization (which didn't get the TLB range information), but it is set up ad-hoc later by the functions that actually flush the TLB. And so any such case that forgot to update the TLB range entries would potentially miss TLB invalidates. Rather than try to figure out exactly which particular ad-hoc range setup was missing (I personally suspect it's the hugetlb case in zap_huge_pmd(), which didn't have the same logic as zap_pte_range() did), this patch just gets rid of the problem at the source: make the TLB range information available to tlb_gather_mmu(), and initialize it when initializing all the other tlb gather fields. This makes the patch larger, but conceptually much simpler. And the end result is much more understandable; even if you want to play games with partial ranges when invalidating the TLB contents in chunks, now the range information is always there, and anybody who doesn't want to bother with it won't introduce subtle bugs. Ben verified that this fixes his problem. Reported-bisected-and-tested-by: Ben Tebulin Build-testing-by: Stephen Rothwell Build-testing-by: Richard Weinberger Reviewed-by: Michal Hocko Acked-by: Peter Zijlstra Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

thp, s390: architecture backend for thp on s390

2012-10-09T07:22:31+00:00

This implements the architecture backend for transparent hugepages on s390. Signed-off-by: Gerald Schaefer Cc: Andrea Arcangeli Cc: Andi Kleen Cc: Hugh Dickins Cc: Hillf Danton Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390/headers: replace s390x with CONFIG_64BIT where possible

2012-05-24T08:10:10+00:00

Replace __s390x__ with CONFIG_64BIT in all places that are not exported to userspace or guarded with #ifdef __KERNEL__. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky